1. Field
This disclosure relates generally to data processing systems, and more specifically, to data processing systems having safe call and return operations.
2. Related Art
In typical data processing systems, a frame stack keeps tracks of procedures called within an executable program. For example, for a called procedure, a frame can be created and placed on a frame stack in memory. This frame may include the local variables of the procedure (which have, for example, overflowed from the registers) as well as the return address to return execution to the caller. However, it is possible that errant software can perform a write to the frame stack causing the return address to be overwritten, thus resulting in the program returning to malevolent code rather than the desired return point. This type of attack may be referred to as a “buffer overflow” attack or a “stack smashing attack”. Therefore, a need exists for improved safety within a data processing system to prevent such attacks.